The hunt for biological, chemical and nuclear weapons in Iraq has come to an end nearly two years after President Bush ordered U.S. troops to disarm Saddam Hussein. The top CIA weapons hunter is home, and analysts are back at Langley.

In interviews, officials who served with the Iraq Survey Group (ISG) said the violence in Iraq, coupled with a lack of new information, led them to fold up the effort shortly before Christmas.

Four months after Charles A. Duelfer, who led the weapons hunt in 2004, submitted an interim report to Congress that contradicted nearly every prewar assertion about Iraq made by top Bush administration officials, a senior intelligence official said the findings will stand as the ISG's final conclusions and will be published this spring.

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President Bush, Vice President Cheney and other top administration officials asserted before the U.S. invasion in March 2003 that Iraq was reconstituting its nuclear weapons program, had chemical and biological weapons, and maintained links to al Qaeda affiliates to whom it might give such weapons to use against the United States.

Bush has expressed disappointment that no weapons or weapons programs were found, but the White House has been reluctant to call off the hunt, holding out the possibility that weapons were moved out of Iraq before the war or are well hidden somewhere inside the country. But the intelligence official said that possibility is very small.

Duelfer is back in Washington, finishing some addenda to his September report before it is reprinted.

'No particular news'
"There's no particular news in them, just some odds and ends," the intelligence official said. The Government Printing Office will publish it in book form, the official said.

The CIA declined to authorize any official involved in the weapons search to speak on the record for this story. The intelligence official offered an authoritative account of the status of the hunt on the condition of anonymity. The agency did confirm that Duelfer is wrapping up his work and will not be replaced in Baghdad.

The ISG, established to search for weapons but now enmeshed in counterinsurgency work, remains under Pentagon command and is being led by Marine Corps Brig. Gen. Joseph McMenamin.

Intelligence officials said there is little left for the ISG to investigate because Duelfer's last report answered as many outstanding questions as possible. The ISG has interviewed every person it could find connected to programs that ended more than 10 years ago, and every suspected site within Iraq has been fully searched, or stripped bare by insurgents and thieves, according to several people involved in the weapons hunt.

Satellite photos show that entire facilities have been dismantled, possibly by scrap dealers who sold off parts and equipment to buyers around the world.

"The September 30 report is really pretty much the picture," the intelligence official said.

"We've talked to so many people that someone would have said something. We received nothing that contradicts the picture we've put forward. It's possible there is a supply someplace, but what is much more likely is that [as time goes by] we will find a greater substantiation of the picture of that we've already put forward."

No accounting of expenditures
Congress allotted hundreds of millions of dollars for the weapons hunt, and there has been no public accounting of the funds. A spokesman for the Pentagon's Defense Intelligence Agency said the entire budget and the expenditures would remain classified.

Several hundred military translators and document experts will continue to sift through millions of pages of documents on paper and computer media sitting in a storeroom on a U.S. military base in Qatar.

But their work is focused on material that could support possible war crimes charges or shed light on the fate of Capt. Michael Scott Speicher, a Navy pilot who was shot down in an F/A-18 fighter over central Iraq on Jan. 17, 1991, the opening night of the Persian Gulf War. Although he was initially reported as killed in action, Speicher's status was changed to missing after evidence emerged that he had ejected alive from his aircraft.

The work on documents is not connected to weapons of mass destruction, officials said, and a small group of Iraqi scientists still in U.S. military custody are not being held in connection with weapons investigations, either.

Three people involved with the ISG said the weapons teams made several pleas to the Pentagon to release the scientists, who have been interviewed extensively. All three officials specifically mentioned Gen. Amir Saadi, who was a liaison between Hussein's government and U.N. inspectors; Rihab Taha, a biologist nicknamed "Dr. Germ" years ago by U.N. inspectors; her husband, Amir Rashid, the former oil minister; and Huda Amash, a biologist whose extensive dealings with U.N. inspectors earned her the nickname "Mrs. Anthrax."

None of the scientists has been involved in weapons programs since the 1991 Gulf War, the ISG determined more than a year ago, and all have cooperated with investigators despite nearly two years of jail time without charges. U.S. officials previously said they were being held because their denials of ongoing weapons programs were presumed to be lies; now, they say the scientists are being held in connection with the possible war crimes trials of Iraqis.

Iraqi 'brain drain'
It has been more than a year since any Iraqi scientist was arrested in connection with weapons of mass destruction. Many of those questioned and cleared have since left Iraq, one senior official said, acknowledging for the first time that "brain drain" that has long been feared "is well underway."

"A lot of it is because of the kidnapping industry" in Iraq, the official said. The State Department has been trying to implement programs designed to keep Iraqi scientists from seeking weapons-related work in neighboring countries, such as Syria and Iran.

Since March 2003, nearly a dozen people working for or with the weapons hunt have lost their lives to the insurgency. The most recent deaths came in November, when Duelfer's convoy was attacked during a routine mission around Baghdad and two of his bodyguards were killed.